1. Field
This invention relates to implements adapted for spreading and otherwise distributing fluid or semi-fluid material. More particularly, the invention is directed to implements for use in spreading paste-like materials such as plaster, cement, adhesives, or other paste-like material.
2. State of the Art
For centuries, building techniques have involved the use of adhesives, plaster, cement and other paste-like materials. Many construction techniques require means of removing a paste-like material from a supply thereof and transferring a given quantity to an application site. Thereafter, the means is often used to spread the material over the application site to achieve a selected thickness preparatory to the application of another building material, such as flooring, tile or other material.
Trowels of various configurations have been used for many years to effect the aforesaid function. In appearance, a trowel conventionally includes a flat planar blade which is oftentimes quadrilateral in shape. A handle is fixedly mounted to the blade to extend uprightly therefrom, thereby providing a means of manipulating the blade. The handle may include a cylindrically shaped member configured to be grasped by the user. The longitudinal axis of the handle is generally oriented horizontally and parallel to the longitudinal axis of the blade.
Specialized trowels have been developed for use in smoothing out irregularities created during the application of paste-like compounds, wet cement, and adhesive emulsions such as latex, acrylic, asphalt, vinyl, epoxies, and thin set gypsum compounds. Such trowels typically include a blade configured for handling a specific material. For example, a trowel blade adapted for a smoothing plaster-like leveling compounds on walls and floors is generally flat or may have a slight concave curl to the smooth edge of the blade. The longitudinal edges of such trowels are the primary working surfaces. The trowel is used by holding the blade at an acute angle (e.g. 10-35.degree.) to the surface to be worked. Pressure is applied to the trowel as it is drawn across the surface, driving a puddle of leveling compound before it. Due to the abrasive nature of the leveling compounds and the substrate over which these compounds are applied, over time, the edges of the blade are abraded and worn, eventually narrowing the blade. Trowels directed for use in smoothing wet cement include blades configured to be slightly convex across their width and curled in the same direction on the front and back ends. In use, the entire bottom smooth surface of such blades are utilized. Owing to the abrasive nature of the cement being spread and the substrate over which the cement is applied, the blade edges are abraded and actually become razor sharp as the blade narrows. Understandably, over time the blade becomes less effective while also becoming a safety hazard to the user. The moderate or severe wear and abrasion on the blade edges of a trowel appreciably depreciate the functionality of a trowel, specifically when smoothing operations are involved.
Due to the fixed mounting of the trowel blade on the handle, the deterioration of a blade has in the past forced the user to purchase an entire new trowel. Recently, attempts have been made to provide trowels wherein the blade is made removable from the handle. Since handles typically are subjected to minimal wear, one handle may be used with a succession of replacement blades, thereby providing an economical means of meeting the need for efficient trowels.
An example of a detachable handle trowel involves a planar blade defining a pair of keyhole slots positioned spacedly apart therein. The handle includes a pair of outwardly extending nut-fitted bolts. Each bolt is first threaded onto the handle from the bottom by means of its slotted head. A thumb screw is then tightened down against the handle from the top like a jam nut to keep the bolt from rotating loose. If the blade is to be replaced, the thumb screws are first loosened then the screws are loosened from the bottom. In this particular design, the head of the bolt, which passes through the slot, extends below the bottom surface of the blade. This construction destroys the smooth planarity of that bottom blade surface, and hinders the use of the trowel as a means of producing a smooth paste surface since the bolt head is constantly digging into the paste as the blade is driven over the paste.
While the aforesaid trowel has provided a means of some benefit in addressing the above concerns, there continues to be a need for a trowel which at once addresses the problem of providing a replaceable blade capability while simultaneously providing a means of maintaining the smooth planar bottom working surface of the trowel.